Aluminum lasts longer- - - -fiber runs quieter. I have installed cam gears without a press by heating the hub, even the fiber ones, but it takes some practice to get the preheat right. If the machine shop screws up the installation, they're on the hook to replace the part. If you mess it up yourself, you're out of pocket the cost of another gear. Bottom line- - - -you make the call!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!